1. Field of the Invention
The present invention relates to a piston fuel pump for an internal combustion engine.
2. Description of the Related Art
Fuel systems of internal combustion engines are known from the art, in which the fuel is transported from a fuel tank into a fuel rail under high pressure with the aid of a mechanically driven piston fuel pump. For this purpose, a movably supported pump piston is provided in the piston fuel pump, which compresses fuel in a delivery chamber of the piston fuel pump. The pump piston is slidingly guided in a piston bushing through a tight fit, in a sliding manner and having a small sealing gap. For supporting and sealing via a gap seal, the piston bushing must have a certain length and, if necessary, absorb large transverse forces. Therefore, the piston bushing is often manufactured from steel. In addition, due to high tolerance requirements, a so-called “piston pairing” is used, i.e., a certain piston is associated with each pump housing. Furthermore, the cylinder in the pump housing must be extensively honed.